Neuroblastoma represents 8-10 % of all malignant tumors in childhood and is responsible for 15 % of cancer deaths in the pediatric population. Aggressive neuroblastomas are often resistant to chemotherapy. Canonically, neuroblastomas can be classified according to the MYCN (N-myc proto-oncogene protein) gene amplification, a common marker of tumor aggressiveness and poor prognosis. It has been found that certain compounds with chelating properties may show anticancer activity, but there is little evidence for the effect of chelators on neuroblastoma. The effect of new chelators characterized by the same functional group, designated as HLZ (1-hydrazino phthalazine), on proliferation (WST-1 and methylene blue assay), cell cycle (flow cytometry), apoptosis (proliferation assay after use of specific pharmacological inhibitors and western blot analysis) and ROS production (fluorometric assay based on dichlorofluorescein diacetate metabolism) was studied in three neuroblastoma cell lines with different levels of MYCN amplification. The molecules were effective only on MYCN-non-amplified cells in which they arrested the cell cycle in the G0/G1 phase. We investigated the mechanism of action and identified the activation of cell signaling that involves protein kinase C.

• MeSH
• apoptóza MeSH
• chelátory farmakologie   terapeutické užití   MeSH
• dítě MeSH
• jaderné proteiny genetika   MeSH
• lidé MeSH
• nádorové buněčné linie MeSH
• neuroblastom * farmakoterapie   MeSH
• onkogenní proteiny * genetika   metabolismus   farmakologie   MeSH
• proliferace buněk MeSH
• protoonkogen n-myc genetika   metabolismus   terapeutické užití   MeSH
• regulace genové exprese u nádorů MeSH
• Check Tag
• dítě MeSH
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• chelátory MeSH
• jaderné proteiny MeSH
• onkogenní proteiny * MeSH
• protoonkogen n-myc MeSH

Combining low-dose chemotherapies is a strategy for designing less toxic and more potent childhood cancer treatments. We examined the effects of combining the novel thiosemicarbazones, di-2-pyridylketone 4-cyclohexyl-4-methyl-3-thiosemicarbazone (DpC), or its analog, di-2-pyridylketone-4,4-dimethyl-3-thiosemicarbazone (Dp44mT), with the standard chemotherapies, celecoxib (CX), etoposide (ETO), or temozolomide (TMZ). These combinations were analyzed for synergism to inhibit proliferation of three pediatric tumor cell-types, namely osteosarcoma (Saos-2), medulloblastoma (Daoy) and neuroblastoma (SH-SY5Y). In terms of mechanistic dissection, this study discovered novel thiosemicarbazone targets not previously identified and which are important for considering possible drug combinations. In this case, DpC and Dp44mT caused: (1) up-regulation of a major protein target of CX, namely cyclooxygenase-2 (COX-2); (2) down-regulation of the DNA repair protein, O6-methylguanine DNA methyltransferase (MGMT), which is known to affect TMZ resistance; (3) down-regulation of mismatch repair (MMR) proteins, MSH2 and MSH6, in Daoy and SH-SY5Y cells; and (4) down-regulation in all three cell-types of the MMR repair protein, MLH1, and also topoisomerase 2α (Topo2α), the latter of which is an ETO target. While thiosemicarbazones up-regulate the metastasis suppressor, NDRG1, in adult cancers, it is demonstrated herein for the first time that they induce NDRG1 in all three pediatric tumor cell-types, validating its role as a potential target. In fact, siRNA studies indicated that NDRG1 was responsible for MGMT down-regulation that may prevent TMZ resistance. Examining the effects of combining thiosemicarbazones with CX, ETO, or TMZ, the most promising synergism was obtained using CX. Of interest, a positive relationship was observed between NDRG1 expression of the cell-type and the synergistic activity observed in the combination of thiosemicarbazones and CX. These studies identify novel thiosemicarbazone targets relevant to childhood cancer combination chemotherapy.

• Klíčová slova
• Dp44mT, DpC, celecoxib, combined anti-cancer treatment, etoposide, medulloblastoma, neuroblastoma, osteosarcoma, temozolomide, thiosemicarbazones,
• Publikační typ
• časopisecké články MeSH

Di(2-pyridyl)ketone 4,4-dimethyl-3-thiosemicarbazone (Dp44mT) and di(2-pyridyl)ketone 4-cyclohexyl-4-methyl-3-thiosemicarbazone (DpC) are novel, highly potent and selective anti-tumor and anti-metastatic drugs. Despite their structural similarity, these agents differ in their efficacy and toxicity in-vivo. Considering this, a comparison of their pharmacokinetic and pharmaco/toxico-dynamic properties was conducted to reveal if these factors are involved in their differential activity. Both compounds were administered to Wistar rats intravenously (2 mg/kg) and their metabolism and disposition were studied using UHPLC-MS/MS. The cytotoxicity of both thiosemicarbazones and their metabolites was also examined using MCF-7, HL-60 and HCT116 tumor cells and 3T3 fibroblasts and H9c2 cardiac myoblasts. Their intracellular iron-binding ability was characterized by the Calcein-AM assay and their iron mobilization efficacy was evaluated. In contrast to DpC, Dp44mT undergoes rapid demethylation in-vivo, which may be related to its markedly faster elimination (T1/2 = 1.7 h for Dp44mT vs. 10.7 h for DpC) and lower exposure. Incubation of these compounds with cancer cells or cardiac myoblasts did not result in any significant metabolism in-vitro. The metabolism of Dp44mT in-vivo resulted in decreased anti-cancer activity and toxicity. In conclusion, marked differences in the pharmacology of Dp44mT and DpC were observed and highlight the favorable pharmacokinetics of DpC for cancer treatment.

• Klíčová slova
• Di(2-pyridyl)ketone 4,4-dimethyl-3-thiosemicarbazone, anti-cancer agents, di(2-pyridyl)ketone 4-cyclohexyl-4-methyl-3-thiosemicarbazone, metabolism, pharmacokinetics,
• MeSH
• krysa rodu Rattus MeSH
• lidé MeSH
• nádorové buněčné linie MeSH
• potkani Wistar MeSH
• preklinické hodnocení léčiv MeSH
• protinádorové látky metabolismus   farmakokinetika   farmakologie   MeSH
• tandemová hmotnostní spektrometrie MeSH
• thiosemikarbazony metabolismus   farmakokinetika   farmakologie   MeSH
• vysokoúčinná kapalinová chromatografie MeSH
• zvířata MeSH
• Check Tag
• krysa rodu Rattus MeSH
• lidé MeSH
• mužské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• srovnávací studie MeSH
• Názvy látek
• di-2-pyridylketone-4,4-dimethyl-3-thiosemicarbazone MeSH Prohlížeč
• protinádorové látky MeSH
• thiosemikarbazony MeSH

Salicylaldehyde isonicotinoyl hydrazone (SIH) is a lipophilic, tridentate iron chelator with marked anti-oxidant and modest cytotoxic activity against neoplastic cells. However, it has poor stability in an aqueous environment due to the rapid hydrolysis of its hydrazone bond. In this study, we synthesized a series of new SIH analogs (based on previously described aromatic ketones with improved hydrolytic stability). Their structure-activity relationships were assessed with respect to their stability in plasma, iron chelation efficacy, redox effects and cytotoxic activity against MCF-7 breast adenocarcinoma cells. Furthermore, studies assessed the cytotoxicity of these chelators and their ability to afford protection against hydrogen peroxide-induced oxidative injury in H9c2 cardiomyoblasts. The ligands with a reduced hydrazone bond, or the presence of bulky alkyl substituents near the hydrazone bond, showed severely limited biological activity. The introduction of a bromine substituent increased ligand-induced cytotoxicity to both cancer cells and H9c2 cardiomyoblasts. A similar effect was observed when the phenolic ring was exchanged with pyridine (i.e., changing the ligating site from O, N, O to N, N, O), which led to pro-oxidative effects. In contrast, compounds with long, flexible alkyl chains adjacent to the hydrazone bond exhibited specific cytotoxic effects against MCF-7 breast adenocarcinoma cells and low toxicity against H9c2 cardiomyoblasts. Hence, this study highlights important structure-activity relationships and provides insight into the further development of aroylhydrazone iron chelators with more potent and selective anti-neoplastic effects.

• MeSH
• aldehydy chemie   farmakologie   toxicita   MeSH
• antioxidancia chemie   farmakologie   MeSH
• buněčné linie MeSH
• chelátory železa chemie   farmakologie   MeSH
• hydrazony chemie   farmakologie   toxicita   MeSH
• lidé MeSH
• MFC-7 buňky MeSH
• myoblasty účinky léků   MeSH
• oxidační stres účinky léků   MeSH
• peroxid vodíku toxicita   MeSH
• protinádorové látky chemie   toxicita   MeSH
• vztahy mezi strukturou a aktivitou MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• aldehydy MeSH
• antioxidancia MeSH
• chelátory železa MeSH
• hydrazony MeSH
• peroxid vodíku MeSH
• protinádorové látky MeSH
• salicylaldehyde isonicotinoyl hydrazone MeSH Prohlížeč

Thiosemicarbazones (TSCs) are an interesting class of ligands that show a diverse range of biological activity, including anti-fungal, anti-viral and anti-cancer effects. Our previous studies have demonstrated the potent in vivo anti-tumor activity of novel TSCs and their ability to overcome resistance to clinically used chemotherapeutics. In the current study, 35 novel TSCs of 6 different classes were designed using a combination of retro-fragments that appear in other TSCs. Additionally, di-substitution at the terminal N4 atom, which was previously identified to be critical for potent anti-cancer activity, was preserved through the incorporation of an N4-based piperazine or morpholine ring. The anti-proliferative activity of the novel TSCs were examined in a variety of cancer and normal cell-types. In particular, compounds 1d and 3c demonstrated the greatest promise as anti-cancer agents with potent and selective anti-proliferative activity. Structure-activity relationship studies revealed that the chelators that utilized "soft" donor atoms, such as nitrogen and sulfur, resulted in potent anti-cancer activity. Indeed, the N,N,S donor atom set was crucial for the formation of redox active iron complexes that were able to mediate the oxidation of ascorbate. This further highlights the important role of reactive oxygen species generation in mediating potent anti-cancer activity. Significantly, this study identified the potent and selective anti-cancer activity of 1d and 3c that warrants further examination.

• MeSH
• biologický transport účinky léků   MeSH
• kyselina askorbová metabolismus   MeSH
• lidé MeSH
• nádorové buněčné linie MeSH
• oxidace-redukce účinky léků   MeSH
• proliferace buněk účinky léků   MeSH
• protinádorové látky chemická syntéza   chemie   farmakologie   MeSH
• racionální návrh léčiv * MeSH
• thiosemikarbazony chemická syntéza   chemie   farmakologie   MeSH
• vztahy mezi strukturou a aktivitou MeSH
• železo chemie   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• kyselina askorbová MeSH
• protinádorové látky MeSH
• thiosemikarbazony MeSH
• železo MeSH

Recent studies have demonstrated that several chelators possess marked potential as potent anti-neoplastic drugs and as agents that can ameliorate some of the adverse effects associated with standard chemotherapy. Anti-cancer treatment employs combinations of several drugs that have different mechanisms of action. However, data regarding the potential interactions between iron chelators and established chemotherapeutics are lacking. Using estrogen receptor-positive MCF-7 breast cancer cells, we explored the combined anti-proliferative potential of four iron chelators, namely: desferrioxamine (DFO), salicylaldehyde isonicotinoyl hydrazone (SIH), (E)-N'-[1-(2-hydroxy-5-nitrophenyl)ethyliden] isonicotinoyl hydrazone (NHAPI), and di-2-pyridylketone 4,4-dimethyl-3-thiosemicarbazone (Dp44mT), plus six selected anti-neoplastic drugs. These six agents are used for breast cancer treatment and include: paclitaxel, 5-fluorouracil, doxorubicin, methotrexate, tamoxifen and 4-hydroperoxycyclophosphamide (an active metabolite of cyclophosphamide). Our quantitative chelator-drug analyses were designed according to the Chou-Talalay method for drug combination assessment. All combinations of these agents yielded concentration-dependent, anti-proliferative effects. The hydrophilic siderophore, DFO, imposed antagonism when used in combination with all six anti-tumor agents and this antagonistic effect increased with increasing dose. Conversely, synergistic interactions were observed with combinations of the lipophilic chelators, NHAPI or Dp44mT, with doxorubicin and also the combinations of SIH, NHAPI or Dp44mT with tamoxifen. The combination of Dp44mT with anti-neoplastic agents was further enhanced following formation of its redox-active iron and especially copper complexes. The most potent combinations of Dp44mT and NHAPI with tamoxifen were confirmed as synergistic using another estrogen receptor-expressing breast cancer cell line, T47D, but not estrogen receptor-negative MDA-MB-231 cells. Furthermore, the synergy of NHAPI and tamoxifen was confirmed using MCF-7 cells by electrical impedance data, a mitochondrial inner membrane potential assay and cell cycle analyses. This is the first systematic investigation to quantitatively assess interactions between Fe chelators and standard chemotherapies using breast cancer cells. These studies are vital for their future clinical development.

• MeSH
• aldehydy farmakologie   MeSH
• chelátory železa farmakologie   MeSH
• cyklofosfamid analogy a deriváty   MeSH
• deferoxamin farmakologie   MeSH
• doxorubicin MeSH
• fluoruracil MeSH
• hydrazony farmakologie   MeSH
• lidé MeSH
• methotrexát MeSH
• MFC-7 buňky MeSH
• paclitaxel MeSH
• proliferace buněk účinky léků   MeSH
• protinádorové látky farmakologie   MeSH
• protokoly protinádorové kombinované chemoterapie farmakologie   MeSH
• synergismus léků MeSH
• tamoxifen MeSH
• thiosemikarbazony farmakologie   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• aldehydy MeSH
• chelátory železa MeSH
• cyklofosfamid MeSH
• deferoxamin MeSH
• di-2-pyridylketone-4,4-dimethyl-3-thiosemicarbazone MeSH Prohlížeč
• doxorubicin MeSH
• fluoruracil MeSH
• hydrazony MeSH
• methotrexát MeSH
• paclitaxel MeSH
• perfosfamide MeSH Prohlížeč
• protinádorové látky MeSH
• salicylaldehyde isonicotinoyl hydrazone MeSH Prohlížeč
• tamoxifen MeSH
• thiosemikarbazony MeSH

SIGNIFICANCE: Anthracyclines (doxorubicin, daunorubicin, or epirubicin) rank among the most effective anticancer drugs, but their clinical usefulness is hampered by the risk of cardiotoxicity. The most feared are the chronic forms of cardiotoxicity, characterized by irreversible cardiac damage and congestive heart failure. Although the pathogenesis of anthracycline cardiotoxicity seems to be complex, the pivotal role has been traditionally attributed to the iron-mediated formation of reactive oxygen species (ROS). In clinics, the bisdioxopiperazine agent dexrazoxane (ICRF-187) reduces the risk of anthracycline cardiotoxicity without a significant effect on response to chemotherapy. The prevailing concept describes dexrazoxane as a prodrug undergoing bioactivation to an iron-chelating agent ADR-925, which may inhibit anthracycline-induced ROS formation and oxidative damage to cardiomyocytes. RECENT ADVANCES: A considerable body of evidence points to mitochondria as the key targets for anthracycline cardiotoxicity, and therefore it could be also crucial for effective cardioprotection. Numerous antioxidants and several iron chelators have been tested in vitro and in vivo with variable outcomes. None of these compounds have matched or even surpassed the effectiveness of dexrazoxane in chronic anthracycline cardiotoxicity settings, despite being stronger chelators and/or antioxidants. CRITICAL ISSUES: The interpretation of many findings is complicated by the heterogeneity of experimental models and frequent employment of acute high-dose treatments with limited translatability to clinical practice. FUTURE DIRECTIONS: Dexrazoxane may be the key to the enigma of anthracycline cardiotoxicity, and therefore it warrants further investigation, including the search for alternative/complementary modes of cardioprotective action beyond simple iron chelation.

• MeSH
• antioxidancia chemie   farmakologie   MeSH
• antracykliny škodlivé účinky   chemie   farmakologie   MeSH
• chelátory škodlivé účinky   chemie   farmakologie   MeSH
• kardiotonika škodlivé účinky   chemie   farmakologie   MeSH
• kovy škodlivé účinky   MeSH
• lidé MeSH
• myokard metabolismus   MeSH
• oxidace-redukce MeSH
• oxidační stres * MeSH
• protinádorové látky škodlivé účinky   chemie   farmakologie   MeSH
• razoxan škodlivé účinky   chemie   farmakologie   MeSH
• reaktivní formy kyslíku metabolismus   MeSH
• signální transdukce * MeSH
• srdce účinky léků   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• přehledy MeSH
• Názvy látek
• antioxidancia MeSH
• antracykliny MeSH
• chelátory MeSH
• kardiotonika MeSH
• kovy MeSH
• protinádorové látky MeSH
• razoxan MeSH
• reaktivní formy kyslíku MeSH